


Knot the Ty

by PineByPine (Tyrannosaurus_Sex)



Series: Three Saplings (A Triplets AU Series) [8]
Category: Gravity Falls
Genre: Aged-Up Character(s), Gender or Sex Swap, Multi, Threesome - F/F/M, Threesome - F/M/M, Triplets, Werewolves
Language: English
Status: Completed
Published: 2019-07-05
Updated: 2019-07-05
Packaged: 2020-06-15 08:56:42
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,653
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19610719
Author URL: https://archiveofourown.org/users/Tyrannosaurus_Sex/pseuds/PineByPine
Summary: The saucy follow up to the previous. Besought by the wereflu, what shenanigans happened on their little camping trip.





	Knot the Ty

Dipper roused from sleep to the feeling of a hand stroking the fur of his neck, short nails just scratching at the skin beneath. He rolled onto his back and smiled, letting a happy little sound escape his throat. He felt the body next to him move and in a moment, Ty was over him, her knees planted on either side of his body. He saw pointy ears twitch atop her head in the darkness.

She leaned down and kissed him, slipping her tongue into his mouth to dance over his own. He felt sharp teeth prick his skin as she nibbled on his lip and moaned a little as their mouths parted. Her eyes narrowed at him in the dim light of the tent.

“I’m hungry, brother.”

He swallowed. “You sure about this?”

She buried her nose into the crook of his neck and made small growling noise. “Yes. Can’t help it. Driving me wild.”

Dippers hands rose to grip her hips and draw her closer to him. God damnit, she smelled good. He wasn’t sure he had another go in him, after all the activity earlier in the evening, but that intoxicating perfume of his sister’s body so close to him was doing everything in its power to make him want to give it a go.

His cock seemed optimistic as well and was already sliding from its sheath into the chill night air. She shifted over him and he felt the folds of her vulva slide along the exposed skin of his shaft. She was wet, very wet. She ground her hips into him and he felt her slickness glide along him.

“Please, Dip.” She whispered, her voice cracking piteously. “I need it. Please.”

He found his mouth was on her throat, nibbling at the fine fur there. He hadn’t really remembered doing that. Whatever this wereflu was doing to his head was still very strong. He pulled his lips away and gave a glance to their sister’s sleeping form, so close she was almost on top of them. “Should we….”

His lips were caught up in another deep, devouring kiss and he felt Ty’s nails as pinpricks on his neck. When the kiss broke, her voice was rasped around the edges with heat. “Let her sleep. I know she had you earlier when I was napping. The tent still reeks of it.” She drew in a deep breath through her nose. “But if you’re not up for it, maybe I’ll wake our dear sister.” She rose a little and Dipper could feel the tip of his cock resting between her lips. She was wet, so wet. “Show her the mess she’s made and see if I can get her to clean it up with her tongue.”

An anchor chain couldn’t have stopped Dipper’s hips as he thrust into his sister. She felt hot around him and he could feel her twitch with pleasure. She exhaled like a weight had been lifted from her shoulders. 

“Good boy.”

He moved as slowly as he could. In so little time his worry had moved from being able to perform at all to being able to last long enough to satisfy. The heat of her, her smell, the firm suppleness of her body, and, oh god, the way she was looking at him like he was just the sexiest fucking thing in the world; he wasn’t sure he could hold back.

* * *

Ty tapped her sister daintily on the shoulder. “Uh Mabes.”

Her sister didn’t stir. 

Ty sighed, grabbed her sister by a furred shoulder, and shook her. “Wake up!”

Mabel rubbed sleep from her eyes. “What the heck Ty? I was having a good dream.”

“I need some help.” Ty pleaded.

Mabel looked her sister over and stifled a giggle behind a hand. Ty still straddled Dipper, who was already so deep into dreamland that a trail of drool was starting to form from the corner of his mouth. “Oh Ty-dye, you didn’t.”

“It wasn’t exactly thinking straight and I’m blaming you. I woke up and smelled what _you’d_ been doing. I got all ramped up and it was fucking hot and...”

Mabel pushed herself into a sitting position and craned her neck to assess the situation. “At least I had it together enough to have him pull out and finish on my chest.” Idle fingers ran through the matted, cowlicked fur of her collarbone. 

“Yea well, in hindsight I’d have done the same thing. Then I could lay back down now.”

“I bet it was at least pretty hot when came in you, though.”

“Yes.” Ty knew she would be blushing if her skin was still visible. She chewed a lip. “It was the business. I came at the same time and another right after. Never got two back to back before. But by the time I calmed down Dip was conked out and I realized I’m stuck. It’s been like ten minutes, my knees are getting sore, and I feel like a stuffed turkey. What am I supposed to do?”

Mabel shrugged. “I guess you just wait for it to shrink back down or you just, you know…” She balled one hand into a fist, grasped the other around the wrist and mimed pulling the former through the latter. She made a popping sound with her lips.

Ty shook her head. “Doesn’t work like that; my junk is holding on to him as much as the other way around.”

The eldest triplet leaned over her brother’s head and poked his face. “Dip’s out like the dead, too.” She glanced back at her sister, then did a double take. “Whoa, I can see the outline.”

Ty startled. “What? No, you can’t!” She took in a sharp breath as Mabel’s hand pressed experimentally against the spot just above where Ty was temporarily fused with her sibling. She reflexively moved at the touch and the swollen member inside her was suddenly quite front and center of her attention.

Mabel rose and straddled Dipper’s chest, facing Ty. Their brother didn’t even stir at the disturbance. “Well, sounds like we’re waiting then. You want me to grab a pack of cards?”

Ty smirked. “I guess just some company will be enough.”

Mabel sniffed the air. “Wow you weren’t lying about the smell in here. It’s like a locker room meets cat house.”

“We should probably air the tent out in the morning.”

Mabel pursed her lips. “Yea and probably get down to that creek.”

“A bath or two all around is probably in order.”

“Oh yea a bath would be a good idea, too.” Mabel winked at Ty, who sighed in return.

“Are you already suggesting more sex?” Ty looked down and realized that Mabel had a hand idly running a finger across herself. “Are you crazy?”

“Um, maybe. Oh, don’t give me that look Ms. Just-had-two-orgasms-like-a-minute-ago. You yourself were blaming the air in here for making you lose control.” Her hips were actually rocking slightly now.

Ty sighed. “Well, I’d offer to eat you out but I don’t think I can work the angle out pinned in place like this.”

“Fuck that, just come here.” 

Mabel reached one hand out and pulled her sister close by the neck. She met Ty’s open mouth with hers and rubbed herself firmly with her fingertips. Ty laid her hand flat on Mabel’s breastbone and could immediately feel her heart pounding in her chest.

“Wow,” she whispered as she broke the kiss, pressing her forehead to Mabel’s, “you went from zero to a hundred in nothing flat.”

Mabel nodded a little but only whispered. “Fingers.” 

Ty slipped two into her sister and gasped slightly. Were werewolves just extra productive or something? Her sister was actually forming a wet spot in Dipper’s fur. She curled her fingers dutifully and teased at Mabel’s g-spot, feeling her muscles tighten and twitch around her. Mabel cast back her head and howled, waves of pleasure running up and down her taut form. She collapsed forward, resting her head on Ty’s shoulder, clinging to her to stay upright.

They hung like that for a moment, the steamy heat of the tent soaking into them. “Sorry,” Mabel gasped, “I don’t know what it is.”

“Probably a side-effect of the wereflu.” Ty scratched behind her sister’s pointed ear.

“Do you think this is like the chicken pox, where you get it once and then never again, or like a cold, where you can get one every year no matter what you do?”

Ty shrugged.

“I’m not saying I’d exactly mind if it’s like a cold, you know.”

“Yea I get you.” She kissed her sister on the tip of a hernose. Then her eyes went wide and she smacked herself in the forehead.

“What is it?”

Ty pointed at the small bag in the corner. “My toiletry bag, can you grab it? I’m not sure I can reach.”

Mabel swung her leg off her brother, stretched to grab it, and passed it to her sister. 

“I can’t believe I didn’t think of this until now.” She rummaged through the bag and pulled out a silvery necklace. She undid the clasp, then leaned carefully down and looped the chain around Dipper’s neck. She held the amulet in one hand and flipped it round to hide the circle and arrow and show the circle and cross.

A moment later she flopped onto her sleeping bag, heaving a sigh of relief. It was a strangely empty feeling all of a sudden, but her legs had been starting to cramp and being able to straighten them was a delight. She grinned broadly.

Mabel smirked at her. “OK, well now that we have an out, I wish I’d let Dip finish like you did. For curiosity’s sake if nothing else.”

Ty shrugged. “We’ve got a couple of days out here still; you can get the knot treatment in the morning if you want.” She shifted slightly and swore inwardly. Helping Mabel out had been her sisterly duty, but it had been a bad idea if she wanted to get to sleep any time soon; her motor was purring again.

“Why wait ‘till morning?” Mabel reach down and flipped the amulet that rested in Dipper’s fur back over, then undid the chain and handed it back to Ty. “Would you be so kind, dear sister? I promise not to be gentle.”

Mere moment later, Ty slammed Mabel against the turf outside the tent and ran her hands up her sister’ sides. Mabel’s legs wrapped around her hips and pulled her in. She felt teeth on her skin at the crook of her neck, not a harsh bite but sharp, just enough pressure to make it clear that more was available if needed. Mabel let out a low growl and twisted her fingers into the hair at the back of Ty’s head.

The middle triplet let out a low rumble of her own, ears flattening back against her head. She narrowed her eyes, gathered her sisters hands up, and pinned them by the wrists to the grass above her head. “I hope you’re ready, sis.”

“Do your worst.”

Ty angled her hips and drove herself home into Mabel, letting out a small moan of pleasure. Goddamn, fucking a pussy felt good. She dug her toes into the grass behind her for leverage and thrust hard, pleased at the way each brought a small gasp from her sister’s throat. She planted her lips on Mabels and let her tongue dance through there other’s mouth, feeling the lithe body arch and squirm beneath her.

Mabel unhooked her ankles and spread her legs wider, arching her back to adjust the angle of attack. Ty felt the swirling compulsions of her animalistic nature driving her forward like whip cracks. She gave it her all, fucking with furious intent feeling more and more consumed by it until she pulled her mouth from the kiss, threw her head back and howled. Another voice joined her, forming a rising harmony that sailed and twisted through the moonlit night to rebound of hillsides and mountains. Tonight everyone would know there were wolves in Oregon.

She hooked her elbows under Mabel’s knees, leaned forward, and pressed their foreheads together. Eyes met in a steady, fierce gaze and Ty felt some part of her hind brain go wild. She growled again, low, certain. “Mine.”

Mabel whimpered and her muscles went stiff. Ty could feel her sister orgasm around her, could feel the slickness of her pussy around Ty’s cock tighten and twitch, trying to bring forth the…

Hands slammed to the ground on either side of Ty’s shoulders, the sudden heat of a body pressed into her back. Teeth nipped at her ear. Ty’s hindbrain worked on its own, uninterested in what the more civilized parts of her had to say. There was an order to these things, a natural way of the world and at this moment Ty was beta to her core.

The alpha was here now.

She froze and turned to look at him, swallowing dryly. Their eyes met and Ty was amazed to understand her brother’s intentions. She and Mabel would communicate so well by facial expressions alone but that had never been her way with Dipper. Under this waning moon, though, she read him loud and clear.

_Proceed with your fucking, beta. I have plans of my own._

Ty turned back to Mabel, who was ready to catch her mouth in a kiss. She resumed her thrusts but the intensity was gone. She drew slowly in and out, careful to keep her own excitement contained. She wasn’t going to let herself climax until the alpha had approved.

She gasped when a slippery hand cupped her balls as she fucked. She found herself making a happy little noise as the sensation ran up her body. The parts of Ty’s brain not otherwise overtaken by thoughts of animal lust and the pack thanked heaven; his palm and fingers were unmistakably slick with lube and she could guess why.

He teased her for a while while she fucked their sister, but took his time to carefully get her properly lubricated and prepped. Then he entered her. This was not the first time, but it was the first time she’d both fucked and been fucked at once. She felt the alpha’s teeth on her shoulder as he drove himself home into her, using his grip on her to give him leverage. Her head was swimming. She heard her sister howl again and felt the unmistakable feeling of a partner climaxing beneath her.

A sort of tingling sensation was building in her lower body. She turned back to look at the alpha and received a slight nod. She finally completely buried herself in Mabel’s warmth, feeling her sister squirm as she was stretched. She felt cock twitch and as she emptied herself into that warmth. Moments later, the alpha’s back arched, he pulled himself from her, and she felt ropes of sticky heat fall into the fur of her back.

They collapsed into a wet heap on the grass. Ty flipped the little amulet around and slumped off of her sister. A hand found hers and they let their fingers intertwine. Then she found another with her other hand and did the same. They looked up at the moon for a while, trying to catch their breaths.

“Sorry if we woke you up, bro. We came out here to let you get some sleep.” Ty reach over and mussed his ears.

“I’m not sure the other side of the mountain was far enough to keep me out of all that.” He panted. “Fuck me, that was hot.”

Out of the corner of her eye, Ty saw Mabel’s ears flick forward. “Choose your words carefully, Dippinstuff.”

“What? Again? You girls are insatiable.”

Mabel rose and rested her chin on Dipper’s chest. “Anything for our alpha.”


End file.
